From: Wei Yongjun <weiyongjun1@huawei.com> stable inclusion from stable-v4.19.268 commit f5575041ec15310bdc50c42b8b22118cc900226e bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYREK CVE: CVE-2022-49032 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit fc92d9e3de0b2d30a3ccc08048a5fad533e4672b ] KASAN report out-of-bounds read as follows: BUG: KASAN: global-out-of-bounds in afe4404_read_raw+0x2ce/0x380 Read of size 4 at addr ffffffffc00e4658 by task cat/278 Call Trace: afe4404_read_raw iio_read_channel_info dev_attr_show The buggy address belongs to the variable: afe4404_channel_leds+0x18/0xffffffffffffe9c0 This issue can be reproduce by singe command: $ cat /sys/bus/i2c/devices/0-0058/iio\:device0/in_intensity6_raw The array size of afe4404_channel_leds and afe4404_channel_offdacs are less than channels, so access with chan->address cause OOB read in afe4404_[read|write]_raw. Fix it by moving access before use them. Fixes: b36e8257641a ("iio: health/afe440x: Use regmap fields") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Acked-by: Andrew Davis <afd@ti.com> Link: https://lore.kernel.org/r/20221107152010.95937-1-weiyongjun@huaweicloud.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Lin Ruifeng <linruifeng4@huawei.com> --- drivers/iio/health/afe4404.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/iio/health/afe4404.c b/drivers/iio/health/afe4404.c index 11910922e655..56ff178bd07e 100644 --- a/drivers/iio/health/afe4404.c +++ b/drivers/iio/health/afe4404.c @@ -256,20 +256,20 @@ static int afe4404_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct afe4404_data *afe = iio_priv(indio_dev); - unsigned int value_reg = afe4404_channel_values[chan->address]; - unsigned int led_field = afe4404_channel_leds[chan->address]; - unsigned int offdac_field = afe4404_channel_offdacs[chan->address]; + unsigned int value_reg, led_field, offdac_field; int ret; switch (chan->type) { case IIO_INTENSITY: switch (mask) { case IIO_CHAN_INFO_RAW: + value_reg = afe4404_channel_values[chan->address]; ret = regmap_read(afe->regmap, value_reg, val); if (ret) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_OFFSET: + offdac_field = afe4404_channel_offdacs[chan->address]; ret = regmap_field_read(afe->fields[offdac_field], val); if (ret) return ret; @@ -279,6 +279,7 @@ static int afe4404_read_raw(struct iio_dev *indio_dev, case IIO_CURRENT: switch (mask) { case IIO_CHAN_INFO_RAW: + led_field = afe4404_channel_leds[chan->address]; ret = regmap_field_read(afe->fields[led_field], val); if (ret) return ret; @@ -301,19 +302,20 @@ static int afe4404_write_raw(struct iio_dev *indio_dev, int val, int val2, long mask) { struct afe4404_data *afe = iio_priv(indio_dev); - unsigned int led_field = afe4404_channel_leds[chan->address]; - unsigned int offdac_field = afe4404_channel_offdacs[chan->address]; + unsigned int led_field, offdac_field; switch (chan->type) { case IIO_INTENSITY: switch (mask) { case IIO_CHAN_INFO_OFFSET: + offdac_field = afe4404_channel_offdacs[chan->address]; return regmap_field_write(afe->fields[offdac_field], val); } break; case IIO_CURRENT: switch (mask) { case IIO_CHAN_INFO_RAW: + led_field = afe4404_channel_leds[chan->address]; return regmap_field_write(afe->fields[led_field], val); } break; -- 2.17.1